(a) Field of the Invention
This invention relates to the broad field of transfer of liquids while maintaining their sterility and freedom from contamination. More particularly, it relates to the field of filling vials with liquid such as an analgesic for subsequent injection into a patient. Specifically, this invention relates to an adapter for use in the injection of a liquid into a vial while maintaining the sterility of the liquid and of the surfaces of the vial contacted by the liquid.
It has been conventional to provide a vial filled with a liquid for transfer to an injector. Typically the vial is pre-filled at the factory that produces the vial. This standard injector vial arrangement includes a vial body having a cylindrical wall between open and closed ends. A plunger is slidable between the ends while maintaining fluid-tight contact with the cylindrical wall. When the vial is pre-filled, the plunger is near the open end, cooperating with the vial to enclose the liquid.
The plunger has an externally threaded stub projecting toward the open end of the vial. The vial is used with an injector that has a needle that extends all the way through it with a removable cap covering the needle at one end. The other end of the injector body has internal threads that enable it to be threaded onto the externally threaded stub of the vial plunger. As the threaded end of the injector body is threaded into the stub, the point of the needle penetrates the plunger and into the liquid volume.
Upon removal of the cap at the other end of the injector, an injection can be given. The injector body has lateral finger wings that facilitate drawing the injector body toward the vial, pressing the plunger away from the open end of the vial body and pushing the liquid through the needle into the patient.
A need has developed for vial that can be supplied empty to be filled subsequently, such as by a pharmacist. This invention provides an adapter to accommodate such subsequent filling of a vial. In the unfilled vial, which is shipped empty, the plunger is adjacent the closed end of the vial, remote from the open end. There is a removable cap the open end of the vial body. This adapter incorporates a transfer syringe for filling the vial while preventing any contaminating contact with the inner wall of the vial that will come into contact with the liquid a the vial is filled and the plunger is driven toward the open end.
(b) Review of Prior Art
Of the prior art examples that deal with means to fill an ampule from a vial, most have a portion connectable with the liquid-holding receptacle, which is full, and have mechanism to expel the liquid from the receptacle and discharge it into a patient. Means are incorporate to keep the liquid uncontaminated during the time it is transferred from the ampule to the patient or to another location.
The typical prior dispensing arrangement consists of a receptacle such as an ampule or a vial that has a cannula assembly extending into it from one end. Adjacent that end is a plunger and the liquid to be dispensed is on the inside end of the plunger. The cannula is supported so that it can be projected through a rubber seal on the piston whereupon liquid can be dispensed through the cannula by the application of pressure to the liquid, by squeezing or other known means. When the piston has been pushed all the way to the closed end of the ampule, the liquid has been dispensed through the cannula.
In Rinser patent No. 3,547,122 the cannula cannot come near the piston. The liquid is already present in the ampule to be ejected therefrom. There is no cannula and no barrel surrounding the cannula. Pfleger U.S. Pat. No. 3,739,779 also lacks a long cannula and a piston that is penetrated to permit introduction of liquid on the closed side of the piston. Sarnoff U.S. Pat. No. 3,811,441 discloses an elongated cylinder surrounding an ampule, but the patent discloses a cannula that is relatively short and that does not connect to the piston. There is no means for penetrating the piston or for holding the liquid behind the piston.
Burke U.S. Pat. No. 3,870,044 provides a short stroke for its cannula. The device of the Burke patent is designed to have the cannula and associated parts broken off after a single use. There is no means by which the cannula could be extended through a piston. Hurscham U.S. Pat. No. 3,946,732 discloses a means for transferring liquid from one chamber to another for mixing with a solid or other liquid. There is a cylinder that has a member that can be penetrated by a cannula. The patent discloses two separate chambers with means for interconnecting them.
The Larrabee U.S. Pat. No. 3,993,063 is directed to the unloading of a vial and for filling a vial. The patent discloses an outer cylinder but does not include a plunger that is movable from the closed end of a vial receptacle. Gustavsson U.S. Pat. No. 4,564,054 discloses a device for transferring a substance from one vessel to a second vessel and for preventing air contamination. The patent does not provide an adapter for the purpose of the present invention.
Buehler U.S. Pat. No. 4,614,437 discloses no piston that is penetrated. Haber U.S. Pat. No. 4,826,489 discloses a needle in a sheath, but there is no plunger arrangement by which a liquid may be inserted into an ampule. The Haber device is for the delivery of a liquid rather than for the filling of a vial. Tripp U.S. Pat. No. 4,614,515 relates to a delivery system for delivering a liquid from a vial.